I recently picked up a Roamio pro and Mini. I also picked up the MOCA adapter and POE filter from TiVo. I was having issues with my Mini being jumpy on playback or live TV. I read that a different splitter and POE filter could help. The splitter that was there was installed by the cable company and is a 5 - 1000 MHZ. I replaced that with a 5 - 3000 MHZ splitter I picked up locally and installed the POE filter. Mini now seems to be running smooth but I had no Internet access. Apparently my cable modem wouldn't connect. I removed the filter and now the modem connects and Internet access works fine.

Here is my setup:
Cable comes to the house - POE Filter - 2 way splitter
1st line goes to the office to a Actiontec MOCA adapter then to Cable modem
2nd line goes to family room to a Roamio Pro.

With the POE filter, no modem connection and no internet access
Without POE filter, modem connects and have internet access

Anyone know if there a reason why the filter would kill my cable modem/internet access?

I recently picked up a Roamio pro and Mini. I also picked up the MOCA adapter and POE filter from TiVo. I was having issues with my Mini being jumpy on playback or live TV. I read that a different splitter and POE filter could help. The splitter that was there was installed by the cable company and is a 5 - 1000 MHZ. I replaced that with a 5 - 3000 MHZ splitter I picked up locally and installed the POE filter. Mini now seems to be running smooth but I had no Internet access. Apparently my cable modem wouldn't connect. I removed the filter and now the modem connects and Internet access works fine.

Here is my setup:
Cable comes to the house - POE Filter - 2 way splitter
1st line goes to the office to a Actiontec MOCA adapter then to Cable modem
2nd line goes to family room to a Roamio Pro.

With the POE filter, no modem connection and no internet access
Without POE filter, modem connects and have internet access

Anyone know if there a reason why the filter would kill my cable modem/internet access?

When I got my first POE filter I put on the cable coming into my modem and checked the speed, it went to zero, a bad POE filter, I was sent another and that one placed on the cable input of my modem had no effect on my internet speed, then I put that POE filter on my home cable input.

Unless it specifies itself as being directional (which I have yet to see), no, they are not directional.

Even if I had one work in one direction, but not the other, I would still consider it defective, if the manufacturer does not clearly spec it out as being directional.

What things matters most (with any possibility of directional POE filters existing, being put aside), when it comes to POE filters, are:

1. Being in the proper place(s) (being where it should be).

2. Using splitters of the correct specs (the frequencies being correct).

3. NOT using the pass-through (in-line) path through devices like Tuning Adapters, if they aren't designed to deal with accepting/rejecting/passing/blocking all frequencies existing on the coax.

4. The most important place to have a POE filter (even if you don't use MoCA), is BEFORE the first split takes place on your to-the-house (lateral) coaxial cable (for security reasons). Any other placement is merely to keep MoCA frequencies from causing unwanted interference within devices that can't deal with them (like Tuning Adapters), or to make different MoCA network segments within your home.

The latter "segmenting" is for advanced power-users, and/or people who might have differing types of MoCA supporting devices, who need one frequency band to only go to certain devices, and another frequency band to only go to other devices.

This can happen if you have BOTH MSO equipment on MSO equipment frequencies, and non-MSO (like retail TiVo) equipment on retail device frequencies, and/or if you deliberately set up devices on different frequencies.

That sounds more like a matter of being in the wrong place, as opposed to being in the wrong direction.

Splitters "split" (not technically, but that's a long explanation), otherwise they wouldn't be called splitters.

Having a POE filter before, as opposed to after, the "split", is not a directional matter. It's a "being in the wrong place" matter. Just because the same POE filter ends up in one direction, simply due to the placement of the female and male ports, does not a directional matter make.

I'm still standing by my statement that, until somebody can post a link to a POE filter's specs stating it is directional, as opposed to anything else, one that fails to work in one direction, but not the other, is defective.

How do you put one in "the other way around"? I'm so glad somebody asked (no, nobody actually did).

Here's how: Use a short length of Coax on one side to make the male-male aspect mate (a "gender changer"), then use a barrel connector on the other end as a "gender changer", so the coax on that side can connect.

Now you have reversed the male & female port orientation, reversing the directionality, without moving the POE filter from the same leg of the splitter (it remains in the same position, just flipped 180 degrees). I've seen Cox techs do this on more than one occasion.

Apply some logic, and think about port position (Is it on the entry, or exit? Is merely on a different leg on the "out" side of the splitter?). Logic would make it so POE filters would be a major hassle, and create more issues than they resolve, if their male & female ends couldn't be rotated 180 degrees, thus "reversing" them.

I'll wait to see if anybody can provide any proof that any sort of "directional" POE filter truly exists, as opposed to assuming they are directional, due to having male-female ports. If one surfaces, I will research it thoroughly, and make sure it truly is directional, then explain how to install (or not install) it, and where it would belong. Until then, I'll stand by over month of research on the matter, what I've been told (which I always research before I take as fact), and my own experiments/experience in determining whether there is any directionality in a non-defective PoE filter.

Last edited by nooneuknow; 12-26-2013 at 09:37 AM.
Reason: added a few lines

That sounds more like a matter of being in the wrong place, as opposed to being in the wrong direction.

Splitters "split" (not technically, but that's a long explanation), otherwise they wouldn't be called splitters.

Having a POE filter before, as opposed to after, the "split", is not a directional matter. It's a "being in the wrong place" matter. Just because the same POE filter ends up in one direction, simply due to the placement of the female and male ports, does not a directional matter make.

I'm still standing by my statement that, until somebody can post a link to a POE filter's specs stating it is directional, as opposed to anything else, one that fails to work in one direction, but not the other, is defective.

How do you put one in "the other way around"? I'm so glad somebody asked (no, nobody actually did).

Here's how: Use a short length of Coax on one side to make the male-male aspect mate (a "gender changer"), then use a barrel connector on the other end as a "gender changer", so the coax on that side can connect.

Now you have reversed the male & female port orientation, reversing the directionality, without moving the POE filter from the same leg of the splitter (it remains in the same position, just flipped 180 degrees). I've seen Cox techs do this on more than one occasion.

Apply some logic, and think about port position (Is it on the entry, or exit? Is merely on a different leg on the "out" side of the splitter?). Logic would make it so POE filters would be a major hassle, and create more issues than they resolve, if their male & female ends couldn't be rotated 180 degrees, thus "reversing" them.

I'll wait to see if anybody can provide any proof that any sort of "directional" POE filter truly exists, as opposed to assuming they are directional, due to having male-female ports. If one surfaces, I will research it thoroughly, and make sure it truly is directional, then explain how to install (or not install) it, and where it would belong. Until then, I'll stand by over month of research on the matter, what I've been told (which I always research before I take as fact), and my own experiments/experience in determining whether there is any directionality in a non-defective PoE filter.

The POE filters I have had can only be put in in one direction, unless you want to do a sex change on both ends of the filter. OK I guess if you put the filter after the splitter the direction would get reversed. But because when I install the filter I put it on the main feed cable coming into the home before any splitters it goes only one way.

The POE filters I have had can only be put in in one direction, unless you want to do a sex change on both ends of the filter. OK I guess if you put the filter after the splitter the direction would get reversed. But because when I install the filter I put it on the main feed cable coming into the home before any splitters it goes only one way.

Yep. The simplest explanation of what I'm trying to say, in the scenario you describe, is that while you can technically install it only one way (when attaching directly to the splitter leg), due to Female-Male ends, it gets directionality-reversed by going on the opposite side (in or out side of a splitter), and in your situation, you could do that "gender change" with a barrel and some coax, and reverse the ends, while leaving it in the same place (position), just 180 degrees flipped, and whatever length of cable used, that distance away from the splitter. If there is nothing wrong with it, it will work the same, minus the small loss caused by the additional connections (insertion loss).

Perhaps, someday, we will see directional filters. I doubt it, but can't rule it out from happening, or that there may be some oddball one out there that already is.

I've seen Cox "test" them, using the barrel gender-change method, and if they operate differently, they throw them in the garbage. It's the same with every other kind of "trap" or "filter" they use. There is no right or wrong way, directionality-speaking, to install any of them. I'm sure this is by design, and likely costs more than making the same traps and filters directional. It likely makes up for the additional cost, by making it impossible to install in the wrong direction.

While I realize Cox has their own MoCA bands, and we are talking about retail PoE filters, the same ones Cox provides with TA self-install kits, can be purchased online, and can function fine with retail MoCA bands as well (when used in conjunction with the right splitters).

I think where some confusion creeps in, is the very existence of the male end (the one with the center conductor exposed), while all the other traps and filters are female on each end, requiring coax connections on each end. All it takes is a barrel connector screwed into the PoE filter to make both ends female, like all the others.

If a filter is passive, i.e., made up of just resistors, capacitors, and inductors, I don't see any way it could possibly be directional.

It may be far from purely sinusoidal, but that's still an AC waveform going through it, which means it's reversing direction up to millions of times per second.

I pretty much agree.

It's just that there are some who insist they are directional. As I ended my last post with, I think that the mere existence of a gender difference is leading people to draw a false conclusion that by having two genders it means it is directional, thus can only be placed in one position, and are making arguments over which leg of a splitter it belongs on.

While "PoE" means "Point of Entry", it's yet another factor which confuses some. PoE filters can be used to isolate MoCA signals to only the equipment that needs MoCA, and keep those signals out of equipment that doesn't need them, or will operate improperly if those signals aren't filtered, and stopped from entering such devices. So, technically, it's still stopping signals from getting to a "Point of Entry", even though many seem to think the point-of-entry as only being the lateral cable to their home.

If the ones Cox uses and provides, were directional, and only meant for the residence point-of-entry, all the TA self-install kits would not only have wrong directions for placement, but also illustrate them being placed "backwards", going by the "logic" that keeps popping up in all the MoCA and PoE filter threads.